f(x) =

{−8 if −3 ≤ x ≤ 0
{x if 0 < x ≤ 3

Evaluate the given expressions.
b)f(0)=
Teach me how to do this, because I don't seem to get the right answer.
Thank You.

What is there to teach ?

Your function says
f(x) = -8 for all values of x from -3 to 0
then you ask for f(0)
so it has to be f(0) = -8

I don't see what the problem is.